Rotos died in a month? You're doing something wrong. As for good slap strings, I believe the best slap strings are DR Lo-Riders, but they don't really cut it in other areas. Rotosounds are the best all around strings for slapping and fingerstyle playing.

Ernie Ball Hybrid Slinkys give me the best tone and I change my strings after 3 weeks to get a fresh tone. Id rather pay for 2 sets of non coated bass sets that give me great tone, than an elixirs set for 40 bucks that sounds average from the start.